UL 795-2011 UL Standard for Safety Commercial-Industrial Gas Heating Equipment (Seventh Edition Reprint with revisions through and including November 27 2013)《商用和工业用燃气加热设备》.pdf

1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 795 Commercial-Industrial Gas Heating EquipmentUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZE

2、D FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Commercial-Industrial Gas Heating Equipment, UL 795 Seventh Edition, Dated April 6, 2011 Summary of Topics This revision to UL 795 is being issued to remove the reference to the withdrawal date of UL 873

3、 and to address universal upkeep of UL Standards for Safety. These revisions are considered to be non-substantive and not subject to ULs STP process. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. Changes in requ

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9、ept for those paragraphs, sections, tables, gures, and/or other elements of the Standard having future effective dates as indicated in the note following the affected item. The prior text for requirements that have been revised and that have a future effective date are located after the Standard, an

10、d are preceded by a SUPERSEDED REQUIREMENTS notice. NOVEMBER 27, 2013 UL 795 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL NOVEMBER 27, 2013 UL 795 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION

11、OR DISTRIBUTION WITHOUT PERMISSION FROM UL APRIL 6, 2011 (Title Page Reprinted: November 27, 2013) 1 UL 795 Standard for Commercial-Industrial Gas Heating Equipment First Edition November, 1952 Second Edition October, 1964 Third Edition April, 1973 Fourth Edition June, 1994 Fifth Edition July, 1999

12、Sixth Edition October, 2006 Seventh Edition April 6, 2011 This UL Standard for Safety consists of the Seventh Edition including revisions through November 27, 2013. The Department of Defense (DoD) has adopted UL 795 on January 27, 1992. The publication of revised pages or a new edition of this Stand

13、ard will not invalidate the DoD adoption. Comments or proposals for revisions on any part of the Standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at http:/. ULs Standards for Safety are

14、copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way. All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2013 UNDERWRITERS LABORATORIES INC.UL COPYRIGHT

15、ED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL APRIL 6, 2011 COMMERCIAL-INDUSTRIAL GAS HEATING EQUIPMENT - UL 795 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS

16、INTRODUCTION 1 Scope .6 2 Glossary .6 3 Units of Measurement 13 4 Undated References .13 5 Components 13 CONSTRUCTION MECHANICAL 6 General .14 7 Corrosion Protection .15 8 General Components and Devices .15 CONSTRUCTION ELECTRICAL 9 General .16 10 Servicing and Adjustment 16 11 Electrical Enclosures

17、 17 12 Field Wiring Connections 25 13 Internal Wiring 29 14 Separation of Circuits .33 15 Mounting of Components 34 16 Motors and Motor Overcurrent or Overload Protection .35 17 Overcurrent Protection of High-Voltage Control-Circuit Conductors 39 17.1 General .39 17.2 Tapped high-voltage control cir

18、cuits 39 17.3 Overcurrent-protective devices .40 18 Overcurrent Protection of Transformers 41 18.1 High-voltage transformers .41 18.2 Thermal protection .41 18.3 Low-voltage transformers 42 18.4 Overcurrent protective devices .42 19 Switches and Controllers 43 20 Capacitors .44 21 Electrical Insulat

19、ing Material 45 22 Spacings High-Voltage Circuits .45 23 Spacings Low-Voltage Circuits 46 24 Accessibility of Uninsulated Live Parts .47 25 Bonding For Grounding 49 CONSTRUCTION BURNER ASSEMBLIES 26 General 52 27 Combination Gas-Oil Burner Assemblies 53 APRIL 6, 2011 COMMERCIAL-INDUSTRIAL GAS HEATIN

20、G EQUIPMENT - UL 795 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONSTRUCTION BOILERS, FURNACES AND HEATERS 28 General 53 29 Accessibility 54 30 Baffles.55 31 Limit Controls 55 31.1 General .55 31.2 Liquid level limit controls boilers .

21、56 31.3 Pressure limit controls boilers .57 31.4 Temperature limit controls boilers .58 31.5 Temperature limit controls warm air furnaces and heaters 59 32 Installation of External Controls and Fittings on Boilers 59 33 Flue Dampers, Draft Regulators, and Draft Hoods 60 34 Bleeds and Vents .61 35 Ba

22、ses .62 36 Heating Surfaces and Combustion Chambers 62 37 Radiation Shields .62 38 Materials in Air Handling Compartments .63 39 Casings .64 40 Fuel Lines and Components .65 41 Flue Collars 65 42 Air Filters 65 PERFORMANCE 43 General 65 44 Test Installations 67 44.1 Floor-mounted devices 67 44.2 Sus

23、pended furnaces 67 44.3 Unit heaters .71 44.4 Test ducts for furnaces .72 45 Test Methods 72 45.1 Firing conditions 72 45.2 Temperature measurements .73 46 Burner Assembly Tests 77 46.1 Combustion Test No. 1 77 46.2 Combustion air failure Test No. 2 .79 46.3 Undervoltage Test No. 3 80 46.4 Power int

24、erruption Test No. 4 .80A 46.5 Pilot supervision Test No. 5 82 46.6 Ignition, gas-electric high tension Test No. 6 .82 46.7 Ignition, gas-electric hot-wire Test No. 7 .83 46.8 Ignition, gas electric hot-wire Test No. 8 .83 46.9 Ignition, gas electric hot-wire Test No. 9 .84 46.10 Ignition, multiple

25、burner Test No. 10 84 46.11 Delayed ignition Test No. 10A 85 47 Operation Tests 85 47.1 Device limit control cutout Test No. 11 .85 47.2 Continuity of operation for furnaces and heaters Test No. 12 86 47.3 Air ow of horizontal furnaces Test No. 13 .87 48 Temperature Tests 87 48.1 General .87 48.2 Co

26、ntinuous operation Test No. 14 91 APRIL 6, 2011 COMMERCIAL-INDUSTRIAL GAS HEATING EQUIPMENT - UL 795 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 48.3 Blocked inlet of furnaces and heaters Test No. 15 91 48.4 Fan failure of furnaces and

27、heaters Test No. 16 92 48.5 Blocked outlet of furnaces and duct-connected heaters Test No. 17 92 49 Low Water Cutoff of Boilers Test No. 17A 93 50 Short-Circuit Test No. 18 .93 51 Overload Test, High-Voltage Transformers Test No. 18A .95 52 Burnout Test, High-Voltage Transformers Test No. 18B .96 53

28、 Dielectric Voltage-Withstand Test Test No. 19 97 54 Draft Hood Equipped Devices 98 54.1 Blocked outlet Test No. 20 .98 54.2 Downdrafts and updrafts Test No. 21 .98 54.3 Spillage Test No. 22 99 54.4 Draft hood strength Test No. 23 .101 54.5 Condensing-type devices 101 55 Blocked Outlet of Forced or

29、Induced Draft Equipped Condensing Appliances Test No. 24 .102 56 Flame Test .102 57 Strain Relief Test 103 OUTDOOR-USE EQUIPMENT 58 General 103 59 Enclosures 103 60 Field Wiring Connections .106 61 Wiring 106 62 Outdoor-Use Equipment Tests 106 62.1 General 106 62.2 Rain test No. 24 .107 62.3 Wind Te

30、st No. 25 110 62.4 Direct vent system leakage test .111 62.5 Wind tests 113 62.6 Rain test .114 62.7 Load test .114 62.8 Impact test .115 63 Gaskets 118 64 Chromic Acid Dropping Test No. 26 119 MANUFACTURING AND PRODUCTION TESTS 65 General 121 MARKINGS 66 General 122 INSTRUCTIONS 67 General 125 APRI

31、L 6, 2011 COMMERCIAL-INDUSTRIAL GAS HEATING EQUIPMENT - UL 795 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements apply to factory-built gas appliances having inputs of more than 400,000 Btu per hour

32、, per individual combustion chamber which require ame failure and other precautions and which are intended primarily for commercial and industrial installation. The appliances covered by these requirements are comfort heating furnaces, heaters and gas-red boiler assemblies except watertube boilers h

33、aving outputs of 10,000 pounds of steam per hour or more. 1.1.1 These requirements also apply to all high pressure steam and high temperature water gas-red boiler assemblies regardless of Btu per hour input. 1.1.1 added September 21, 2012 1.2 Gas-heating equipment covered by these requirements may b

34、e operated without a competent attendant being constantly on duty at the burners while the appliances are in operation. 1.3 Additional installation and operation requirements are available for central-heating gas appliances, oor furnaces, room heaters, unit heaters, and water heaters as dened by the

35、 National Fuel Gas Code, NFPA 54, and by the Liqueed Petroleum Gas Code, NFPA 58, as applicable. 2 Glossary 2.1 For the purposes of this Standard the following denitions apply. 2.2 AIR HEATER An indirect red vented appliance intended to supply heated air for space heating and other purposes, but not

36、 intended for permanent installation. 2.3 AIR SHUTTER An adjustable device for varying the size of the air inlet or inlets regulating primary or secondary air. 2.4 AIR SHUTTER, AUTOMATICALLY OPERATED An air shutter operated by an automatic control. 2.5 AIR SHUTTER, MANUALLY OPERATED An air shutter m

37、anually set and locked in the desired position. 2.6 APPLIANCE FLUE The ue passages within an appliance. 2.7 ALUMINUM COATED STEEL An aluminum coated steel in which the bond between the steel and the aluminum is an iron-aluminum alloy. 2.8 BAFFLE An object placed in an appliance to direct the ow of a

38、ir or ue gases. 2.9 BASE The main supporting frame or structure of the assembly, exclusive of legs. 2.10 BOILER A closed vessel in which water or some other liquid is heated or steam is generated or superheated, under pressure or vacuum, by direct application of heat. 2.11 BOILER, HIGH PRESSURE STEA

39、M A boiler in which steam is generated at a pressure higher than 15 psig (103 kPa). SEPTEMBER 21, 2012 COMMERCIAL-INDUSTRIAL GAS HEATING EQUIPMENT - UL 795 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 2.12 BOILER, HIGH TEMPERATURE WATER

40、A boiler intended for operation at a pressure exceeding 160 psig (1103 kPa) and at a temperature exceeding or at a temperature exceeding 250F (121C). 2.13 BOILER, HOT WATER A boiler that furnishes hot water at a pressure not exceeding 160 psig (1103 kPa) and at a temperature not exceeding 250F (121C

41、). SEPTEMBER 21, 2012 COMMERCIAL-INDUSTRIAL GAS HEATING EQUIPMENT - UL 795 6AUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL SEPTEMBER 21, 2012 COMMERCIAL-INDUSTRIAL GAS HEATING EQUIPMENT - UL 795 6B No Text on This PageUL COPYRIGHTED MATERI

42、AL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 2.14 BOILER, LOW PRESSURE STEAM A boiler in which steam is generated at a pressure not exceeding 15 psig (103 kPa). 2.15 BURNER GAS A device for the nal conveyance of the gas, or a mixture of gas and air, to the co

43、mbustion zone. 2.16 BURNER, AUTOMATICALLY LIGHTED One where fuel to the main burner is normally turned on and ignited automatically. 2.17 BURNER, MANUALLY LIGHTED One where fuel to the main burner is turned on only by hand and ignited under supervision. 2.18 BURNER HEAD, GAS That portion of a burner

44、 beyond the outlet end of the mixer tube which contains the ports. 2.19 CASING An enclosure forming the outside of the appliance, no parts of which are likely to be subjected to intense heat. 2.20 CHIMNEY CONNECTOR The pipe which connects a fuel burning appliance to a chimney. 2.21 COMBUSTIBLE MATER

45、IAL Combustible material, as pertaining to materials adjacent to or in contact with heat producing appliances, chimney connectors and vent connectors, steam and hot water pipes, and warm air ducts, means material made of or surfaced with wood, compressed paper, plant bers, or other material that wil

46、l ignite and burn. Such material shall be considered as combustible even though ameproofed, re retardant treated, or plastered. 2.22 COMBUSTION As used herein, the rapid oxidation of fuel accompanied by the production of heat, or heat and light. Complete combustion of a fuel is possible only in the

47、presence of an adequate supply of oxygen. 2.23 COMBUSTION CHAMBER The portion of an appliance within which combustion occurs. 2.24 COMBUSTION DETECTOR That part of a primary safety control which is responsive directly to ame properties. 2.25 COMBUSTION PRODUCTS Constituents resulting from the combus

48、tion of a fuel with the oxygen of the air, including the inerts, but excluding excess air. 2.26 CONDENSATE The liquid which separates from a gas, including ue gases, due to a reduction in temperature. 2.27 CONTROL A device designed to regulate the fuel, air, water, or electrical supply to the contro

49、lled equipment. It may be automatic, semi-automatic, or manual. 2.28 CONTROL INPUT, COMBUSTION A control which automatically regulates the ring rate at predetermined air-fuel ratio in accordance with load demand. It may be a type which positions the air and fuel supplies for low re and for high re as required to meet the load demands, or it may be a modulating type whic